Improved synthesis of sterically encumbered heteroaromatic biaryls from aromatic β-keto esters
作者:Brandon R. Rosen、Ehesan Ul Sharif、Dillon H. Miles、Nicholas S. Chan、Manmohan R. Leleti、Jay P. Powers
DOI:10.1016/j.tetlet.2020.151855
日期:2020.5
A protocol for the synthesis of hindered 4-aryl 2-aminopyrimidines from β–keto esters is described. The process employs trifluoroethanol as an essential additive to promote the guanidine condensation reaction, enabling the synthesis of 25 aryl- and heteroaryl substituted aminopyrimidines in good yields and high purities with no column chromatography. The conditions described herein are readily scalable
描述了由β-酮酸酯合成受阻4-芳基2-氨基嘧啶的方法。该方法采用三氟乙醇作为促进胍缩合反应的必要添加剂,无需柱色谱法即可以高收率和高纯度合成25个芳基和杂芳基取代的氨基嘧啶。本文所述的条件易于扩展,并且已用于临床A 2a / A 2b R拮抗剂AB928的大规模合成。